1. Field of the Invention
The present invention relates to an adaptive multiplexing/demultiplexing method, and a multiplexer/demultiplexer using the same in the H.324 system, and more particularly, to an adaptive multiplexing/demultiplexing method capable of being effectively used in an error-prone channel, and a multiplexer/demultiplexer using the method.
2. Description of the Related Art
In general, the H.324 recommendation prescribes a multiplexing of video and audio signals which is effective in an error-prone channel such as a wireless channel, and includes H.223 multiplexing, H.223/Annex A multiplexing, H.245 controlling, H.263 video coder/decoder (CODEC) and G.723.1 audio CODEC. Particularly, according to the H.223 recommendation, in order to achieve video telephone and video conferencing in a general digital telecommunication network by the ITU-T (the Telecommunication standardization sector of the International Telecommunication Union), video, audio and other data are adaptively multiplexed in protocol data units (PDU) and then later demultiplexed. An H.223 multiplexer/demultiplexer (MUX/DEMUX) can be used when a channel bit error rate is 10" or less. An H.223/Annex A MUX/DEMUX is a new MUX/DEMUX capable of improving error robustness, obtained by adding rate compatible punctured convolutional coder/decoder (RCPC CODEC) and automatic retransmission on request (ARQ) functions to the H.223 MUX/DEMUX. According to the H.223/Annex A MUX/DEMUX, when an error occurs in a receiver, the RCPC-encoded data is retransmitted by a transmitter at different rates.
However, it is nearly impossible to use the H.223 MUX/DEMUX in an error-prone channel due to its low error-resiliency. Also, in the case of the H.223/Annex A MUX/DEMUX, channel throughput is steeply decreased due to the ARQ, and there is extremely high complexity due to the RCPC.